In general, wafer manufacturing processes may include mechanical surface treatment processes such as ingot grinding, ingot slicing, or lapping.
The surfaces of wafers may be mechanically damaged due to these mechanical surface treatment processes. The mechanical damage to the wafers may be eliminated by grinding or etching the wafers in post-processing such as grinding or etching.
The amount of the wafer to be removed in post-processing may be determined according to the depth of mechanical damage thereto. To this end, measurement for determining the depth of mechanical damage to the wafer must precede the removal.
The method of measuring the depth of mechanical damage to the wafer may include a method using etching or polishing, a method using X-ray diffractometers, a method using Raman spectroscopy, a method using photoluminescence, or the like.
However, since the method using etching or polishing is a destructive method, it may take a long time to polish and heat-treat the wafer. In addition, the method using X-ray diffractometers may merely determine whether or not the wafer is damaged, and may only determine the extent of damage to the wafer in a qualitative manner. In addition, it is impossible for the method using Raman spectroscopy and the method using photoluminescence to measure the depth of damage to the wafer.